1. Field of Art
This invention relates to two new antibacterial and antitumor agents designated LL-BO1208.alpha. and LL-BO1208.beta. and to their production by fermentation of the novel microorganism Streptoverticillium stramineum or mutants thereof.
2. Prior Art
LL-BO1208.alpha. and LL-BO1208.beta. are novel antibiotics and anti-tumor agents of the bleomycin/phleomycin family. See, e.g., S. M. Hecht (Ed.), Bleomycin: Chemical, Biochemical and Biological Aspects, Springer-Verlag, N.Y., 1979. LL-BO1208.alpha. and LL-BO1208.beta. are differentiated from all other members of this family by their structure, chemical and physical properties, and effects on specific microorganisms. The most closely related known compound is Tallysomycin A [M. Koniski et al., J. Antibiotics 30: 789 (1977)] which, like LL-BO1208.beta., contains .beta.-lysine. These two compounds are the only members of the bleomycin/phleomycin family which contain this particular amino acid. However, Tallysomycin A differs significantly from LL-BO1208.beta. in that Tallysomycin A contains spermidine and an additional sugar moiety, and in addition LL-BO1208.beta. contains a reduced bithiazole ring system.